They're talking about things of which they don't have the slightest understanding, anyway. It's only because of their stupidity that they're able to be so sure of themselves.
And not only the pride of intellect, but the stupidity of intellect. And, above all, the dishonesty, yes, the dishonesty of intellect. Yes, indeed, the dishonesty and trickery of intellect.
Someone said: "I have been prejudiced against myself from my earliest childhood: hence I find some truth in all blame and some stupidity in all praise. I generally estimate praise too poorly and blame too highly.
I certainly must,' said she. 'This sensation of listlessness, weariness, stupidity, this disinclination to sit down and employ myself, this feeling of everything's being dull and insipid about the house! I must be in love; I should be the oddest creature in the world if I were not.